The ac collection system in commercial roof-mounted PV systems generally extends from the inverter ac output terminals to the low-voltage point of interconnection (POI). The exception is when the system interconnects at medium-voltage levels, in which case the ac collection system ends at the low-voltage terminals of the medium-voltage transformer. From a design perspective, the goal of ac circuit aggregation is to field an efficient system that is cost effective; meets building, fire and electrical codes; and satisfies the client. Project stakeholders must locate equipment optimally, route circuits efficiently and size conductors properly. Read more...